1. Field of the Invention
The present invention relates generally to head and helmet mounted displays (HMDs); and, more particularly to a quick adjustment mechanism therefor.
2. Description of the Related Art
Head/Helmet Mounted Displays (HMDs) are often difficult and time consuming to adjust and sometimes require a technician to perform the adjustment for the user. Positioning adjustments are desirable because of anthropometric variability between users. For example, a device affixed in a permanent location on a particular headgear would only lie in the line of sight of a very small portion of the people in a given population. In order to accommodate anthropometric variation, some conventional mechanisms provide a forward tilt, a lateral slide, and a vertical adjustment. Additional features on some mounting mechanisms provide for the removal of the device and/or a flip-away or slide mechanism to allow storage of the device away from the line of sight when not in use. Conventional adjustment mechanisms often require the user to adjust each degree of freedom successively.
U.S. Pat. No. 7,193,783 entitled “Mounting/Adjusting Mechanism for Vision Enhancement System,” discloses a mounting assembly for a vision enhancement device and associated vision enhancement display, the assembly comprising a display mounted to an arm positionable in front of the user's eye, a base member for receiving a cradle for the vision enhancement device and for attaching to a head-mounting platform, and one or more intermediate members for connecting the arm to the cradle. In one embodiment, the mounting system comprises one or more mechanisms for aligning the display optical axis with the vision enhancement device optical axis and with the user's line of sight, one or more mechanisms for orienting the vision enhancement device within multiple degrees of freedom without changing the alignment of the display optical axis with the device optical axis, and one or more mechanisms for toggling the display between an in-use position to at least one storage position, and, optionally, between right eye and left eye positions.
The '783 patent system is relatively complicated and time-consuming. There are multiple interfaces for XYZ and tilt adjustment that result in a multistep process to obtain nominal placement of the image source assembly (ISA) in front of the eye. These interfaces are not intuitively located or designed for easy operation. For example, an inverting arm that attaches to a display slide assembly appears to be flimsy and unstable. This is only implemented in a monocular system. Some of the parts also seem to be very complicated and difficult to manufacture.
U.S. Pat. Application No. 20090243965 entitled, “Lightweight Head Mounted Display with Multiple Adjustments,” discloses an assembly with a frame comprising a base adapted to rest on a top portion of a head of a user, a front frame portion adapted to rest against a front portion of the head of the user, and a rear frame portion adapted to rest against a back portion of the head of the user. The assembly also includes an optical display housing. Additionally, the assembly includes an adjustment mechanism configured to adjust a distance between the front frame portion and the rear frame portion while maintaining the optical display housing at a constant angle relative to the base. The instant abstract is neither intended to define the invention disclosed in the specification nor intended to limit the scope of the invention in any way. The '965 system does not appear to be a quick adjustment mechanism. Interfaces are not intuitive and difficult to find blindly. Also, the '965 mechanism has a very high part count.
U.S. Pat. No. 5,954,642, entitled, “Adjustable Head Mounted Display and System,” discloses a head mounted display that includes a head suspension apparatus and a display coupled thereto. In a stationary state, the display is maintained in a desired position relative to the head suspension apparatus. Further, in a release state, the display is always freely movable both vertically and horizontally relative to the head suspension apparatus. In addition, the display may also always be freely rotatable about an axis of the display as well as vertically and horizontally. The coupling of the display to the head suspension apparatus may be attained using a slide bar and hinge mechanism that forms a rigid triangular structure when the display is in the stationary state. Further, the head suspension apparatus may include an adjustable temporal support element for positioning about the circumference of a user's head and an adjustable crown support connected to the temporal support with the crown support including channels for allowing electrical connection lines to move freely therein.
The '642 mechanism includes a knob in the middle that may be hard to reach/find. The IPD knob adjusts both eyes at once which provides a deficiency because people's faces/eyes are not perfectly symmetrical about the centerline of the head. One eye may be further from the center then the other.
U.S. Pat. No. Des. 415,146, issued to K. Hori, entitled “Head Mounted Display,” discloses the ornamental design for a head mounted display.
NVIS, Inc., Reston, Va., manufactures a modular head mounted display, known as the nVisor MH60-E, that provides motion trackers, eye trackers, and video see-through capabilities. The NVIS device does not appear to provide for very quick adjustment. The user has to move his hands away from the eye relief levers and toward the IPD knobs. This results in a less intuitive process as the user then has to blindly hunt for the knobs which are not visible to the user while wearing the HMD. Furthermore, it is not intuitive as to where the IPD knobs are positioned.
As will be disclosed below, the quick adjustment mechanism of the present invention is designed as an intuitive, easy to use interface for the user to quickly adjust the HMD vertically, tilt, eye relief and interpupillary distance (IPD) in 15 seconds or less.